Pipe-bending machine



W. A. PRATT. PIPE BENDING MACHINE.

APPucATloN FILED 1AN.13.1919.

Patented Nov. 23, 1920.

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WILLIAM A. PRATT, 0F BAYGNNE, COMPANY, OF NEW YORK,

NEW JERSEY, ASSIGNOR TO THE M. W. KELLOGG N. Y., A CORPORATION 0F NEW JERSEY.

rien-BENDING MACHINE.

' Specication of Letters Patent. Patented NOV. 23, 1920.

Application `tiled January 13, 1919. Serial No. 270,996.

lTo @ZZ fro/wm t may conce/m Be it known that I, lWILLIAM A. PRATT, a citizen of the'llnited States, and a resident oi? Bayonne, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Pipe- Berufung Machines, of which the following a description.

liiy invention relates to the art of bending' pipe and the like, and relates more especially to an improvement Von Patent No. 1,268,344, granted to Emil F. Holinger on June 11, 1918.

In said patent to Holinger the length of pipe to be bent is mounted in a rack on a iiXed bed or support and a carriage is provided which may be moved longitudinally ot' the pipe and which carries a pivoted arm adapted to be fixed to the pipe for bending,` the pipe around a roller as the carriage is moved. In said patent, the pivoted arm is clamped at its free end to the pipe and when the arm has turned through an angle of 90, it is nccessary'to reset the clamping means if it is desired to bend the pipe through larger angle.

It is accondingly the principal object of invention to provide means whereby an apparatus having a single pivoted arm similar to that oi' thesaid l-lolinger patent may be used to malte bends of any desired are with a maximum speed and convenience.

A further objectof my invention is to improvecertaindetails of constructionV of said Holinqer apparatus.

ln thev drawingr accompanying and torminp part of this specification, Y

Figure 1 is a longitudinal sectional view of an apparatus embodying my invention., showing the position of the parts inst fore starting to bend a leneith of pipe.

Fig. f2 is an end view of the apparatus shown in Fig. 1, taken from the left of Fig. 1^. l,

Fig. 3 is a view similar to Fie. 1, but showing theparts inthe position occupied after the bending` action has progressed a certain distance.

Fig. 4 is a detail showing means whereby the position ot' the axis of the pivoted arm may be shifted.

Fig. 5 is a side view of the parts shown in Fig. fi.

Fig 6 is a detail view illustrating the slotted pin appearing in Figs. 1 to 5 inclusive.

Referringto the drawing in detail, 1 is the bed or framework of the machine on which is mounted a concave support 2 for .receiving the pipe 3 to be bent. Thev member 2vwith a stop 4t constitute a rack for the pipe during; the bendingT operation. A carriage 5 is mounted on the frame 1 and is provided with wheels 6 adapted to support the carriage and to` permit its being moved longitudinally alongthe frame. The wheels 6 are moved in .fruidcwavs 7 formed in the side members of the frame, and hold the carriage in operative relation'at all times. The carriage 5 carries a bending roller S. adapted to move in contact with the pipe disposed in the trame, and the pipe is bent around this roller as hereinafter explained. The carriage 5 also carries a swinging or pivoted rieid arm 9. secured at one end toa pivot pin 10. said arm 9 swingingV on the outside of the carriage 5 to promote convenience of construction. The arm 9' is made in two sections. as shown', said sections being mounted on the outside of the carriage. and its outer end carries a bearing roller 11l adaptedv to yexipgafrre the pipe to be bent on theside opposite. The pipe is provided preferably with a clamp'. such .as 12,l or other suitable means to' prevent the roller 11 from running'r1 alonf'i the pipe durQ ing the kErst phase of the bendingoperation". This clamp k12 fits snugly against the' roller 11 and by its friction prevents the roller from turning onV its own axis, and thus causes an outwardv thrust to be given to the trame 9 the instant thecarriage 5 is moved.

'lt will `be seen that If have arranged the arm 9"l slie'htly different with respect to` the carriage than in .the patent, to Holinfrer, above mentioned, andV that I havcjprovifded a roller' at the end of the arm 9 instead of a shoel as in said patent. but that aside freni these two differences, the parts heretofore described have been the same and .had the same arraiwement as in said patent.' How ever, accordingr to my invention, the carriage" 5 is provided with a stop means.` such as 13, which projects into the path of the arm 9 and prevents the arm 9 from swinging' more than a certain distance from its initial position. the initial position of the arm 9 being shown in Fig. 1, and the position assumed by the arm when held by stop 13 being shown in Fig. 3. The stop 18 is shown as i'ixed rigidly to an extensiond of the carriage 5. The stop 13 is preferably de signed to holdthe arm 9 at an angle of 45 from its vertical initial position, but it will be understood that this angle may be varied to a considerable extent from that stated, without altering the mode of action of the machine or apparatus. i

While an arm 9 of the length shown in the drawing is the one most commonly used, and while for an arm of the said length it is most satisfactory to use a stop which is a permanent part of the frame, 1 provide `also a separable stop, such as le, which may he placed on any one of the bosses 15 which .project from the inside of the frame and which cooperate with armswhich may be used in place of arms 9 and which are of less length than arms 9, the method of cooperation between arms 9 and stop 14: and such shorter arms (not shown) being described hereinbelow.V

1n bending thin pipe, it is preferable to use an interior support or head, such as 16, which is connected to the carriage by the tension rod 17 so as to always be maintained immediately beneath bending roller 8. This feature is, of course, well known.

In bending lengths of flanged pipe,'1 have found that it effects important economies in time to provide special means whereby the roller 11 may be slipped over the flange of the pipe after the latter has been placed on the bed 2 of the machine. For this purpose, I prefer to use eccentrics, such as 18,'from which the arm 9 is hung, and which are mounted on the ends of the pin and prevented from turning with respect thereto by means of keys, such as 19. A wheel, such as 20, is provided for' turning the pin 10 and thus the eccentrics 18, so as to vary the effec tive length of arm 9 so that the roller 11 may pass the flange of the pipe and then be brought up against the body thereof. I provide also pins, such as 21, which project into' semicircular slots 22 in the eccentrics so as to provide positive indication to the operai tor when the eccentrics are at one or the other limit of their throw, from the fact of the pins striking the ends of the slots.

The operation of the machine above de scribed is as follows: The pipe to be bent is placed in the frame, as shown in Fig. 1. An arm 9, corresponding in length to the radius to which the pipe is to be bent, is then selected and the parts arranged as in Fig. 2.

'ljhe carriage 5 is then drawn toward the right in Fig. 1. As soon as the carriage moves, the arm 9 is forced to swing upwardly in an arc, the roller 11 bending the pipe as the arm swings, but without decided relative movement between the two. As soon, however, as the arm 9 strikes the stop 13, further movement ofthe arm is prevented. The stop 12 is now removed from the pipe, although it may also be removed at any time after a slight bending of the pipe has occurred. .The continued movement of the carriage 5 forces the pipe to run over the roller, turning the latter, and at the same time continuing to bend the pipe on an arc whose radius is the length of the arm 9. Consequently a bend of any desired length of arc may be made without changing the position or adjustment of the swinging arm or the rollers.

l wish it to be understood that 1 consider the combination of a roller on the end of a rigid pivoted arm having a limited arc of movement to be the essential feature of my invention and that this. can be used in any apparatus in which there is relative movement between the pivot of the arm and the pipe to be bent. Y

Having thus described my invention, l claim:

1. A pipe bendingmachine comprising in combination a rigid arm, a pivotal mounting for one end of said arm, whereby said arm can swing freely during the bending of a given pipe, a roller at the other end of said arm for contacting with one side of the pipe to be bent, a roller for contacting with the other side of the pipe, means whereby Y relative movement may be produced between said ysecond mentioned roller and said pipe, and vstop means lying on the same side of the line of the pipe before bending as the axis of rotation of said arm and contacting `with said arm only at one limit of its arc of movement for defining the position of the arm at the end of the bendingaction.A

2. 1n a pipe bending machine in combina of said arm is .pivotally connected, a roller at the other end of said arm for contacting with one 1side of the pipe toy be bent, a roller mounted on said frame for contacting with the opposite side of said pipe,means whereby relative movement may be kproduced 4b e-` V tween said secondmentioned roller and said pipe, and stop means fixed Aon saidframe and lying on the same side of the pipe as said second roller for limiting the arc of swing of said arm, said arm being mounted to Swing freely for a certain distance during the bending of a given pipe.

WILLIAM A. PRATT.

105 tion, a rigid arm, a frame to which one end n 

